Martin Brody is the new police chief of Amity, an island town somewhere in New England. He has a wife named Ellen, and two sons named Michael and Sean. On a Summer morning, Brody is called to the beach, where the mangled body of Summer vacationer Chrissie Watkins has washed ashore. The medical examiner tells Brody that it could have been a shark that killed Watkins. Mayor Larry Vaughn, who is desperate to not lose the money that will be brought in by 4th of July tourists, wants Brody to say Watkins’s death was caused by a motorboat propeller instead of a shark, because the thought of a shark in Amity’s waters would drive tourists away from Amity.